That sure seems to stick out a lot. Is it visible when standing or sitting? As assume it is a rare occasion that you are lying on your kitchen floor! ;)

I think the only issue is that the stone is weak where it is missing. I would look for a foam to fill in the cavity.

Only visible from the floor. The contractor was offended that I even commented on it. N since I know it is there I want it covered. What kind of foam?

I am not sure why the undercounter looks like this either but how do I get it to look finished? Any suggestions?

Could I use cement to finish this off.